Power



United States Patent greases V contra-oi APRARATUS USlNG sneer waysnivsnov Joseph E. Wallace, Endicott, N.Y., assignor to ln'ternw tionalBusiness Machines tiurporation, New York, NE a corporation oi New YorkFiled .luly 2'7, 1962, tier. N 2.112525 11 Claims. (6i. EARL-83) Thisinvention relates to control apparatus actuated by the shockwave energyfrom a controlled electrical discharge, and more particularly relates toan improved high-speed electrical switching device actuated by shockwaveenergy.

Solid state switching devices and reed relays are two types ofcommercially available switching devices that are capable of completingelectrical circuits in less than 1 millisecond. Solid state devicesswitch very rapidly; but in this class of devices, the contact is of lowimpedance or high impedance-in other words, never completely open. Reedrelays can be used to control circuits having relatively high currents;but they must be used in low-voltage circuits because the reeds areseparated by very small gaps, such as about .003 inch. Hence, it thereeds formed part of a circuit including a source of high potential,such as 1,900 volts, breakdown of the air gap undoubtedly would occur;and also arcing of the con tacts and contact wear would increasesubstantially. Moreover, since the operating time or a relay isdependent upon the air gap, a slight increase in air gap will result ina substantial increase in the operating time of the reed relay. Also,reed relays are subject to contact wear due mainly to contact bouncefrom the high impact kinetic energy of the reeds.

Furthermore, with conventional electromagnetic relays, the energyavailable at the instant the energizing circuit is closed isapproximately zero. This energy must thereafter build up to apredetermined degree before the armature will move.

One object of this invention is therefore to provide an improved controlapparatus including a movable control member that is variouslypositionable by shockwave energy produced by a controlled electricaldischarge.

Another object of this invention is to provide an electrical switchingdevice which can be controlled from a high-voltage source to completecircuits capable of carrying relatively high currents.

Another object is to provide a high-speed electrical switching device inwhich contact bounce is substantially eliminated and contact wear isaccordingly minimized, and fast response times are accomplished despiterelatively large air gaps.

Still another object of this invention is to provide an electricalswitching device which will remain latched in position after dissipationof the shoclrwave energy.

A further object of this invention is to provide an electrical switchingdevice wherein the energy available at the instant of actuation is at amaximum (rather than a minimum).

According to these objects, the device embodying the invention comprisesa flexible strip anchored at one or both ends. A pair of coaxiallyaligned electrodes have their tips separated by an air gap provided in arecess disposed at one side of the flexible strip. When a high voltagesource is connected to these electrodes, the gap will be ionized. Theresultant shocltwave is focused against the side of the flexible stripto shift it laterally to perform a desired control operation; e.g.,translationally shift a contact element to a circuit-making or circuit-3,160,?23v l atentecl Dec. 8, 1964 lowing more particular description ofpreferred embodiments of the invention, as illustrated in theaccompanyins drawing, wherein:

FIG. 1 is a schematic View of a control apparatus including a pair ofhigh-speed electrical switching devices constructed according to oneembodiment of the invention to provide transfer-type switchingoperations in both directions as a result of shockwave energy;

FIG. 2 is a variation of the arrangement shown in FIG. 1, in that itshows a single switching device actuated to one position by shockwaveenergy and mechanically returned to a normal position; and

H65. 3 and 4 are modified versions of the switching devices shown inFEGS. l and 2, wherein a flexible shockwave-actuated contact controlmember is cantilever supported at one end instead of at both ends.

DESCRIPTION As shown in PEG. 1, the apparatus constructed according tothis embodiment of the invention comprises a pair ofelectrically-controiled switching devices, it it). As illustrated, eachor" these devices comprises a pair of coaxially aligned electrodes Ill,that are embedded or otherwise carried within a ceramic electrode block13. The tips of the electrodes are separated by an air gap. This gap isprovided within a bore-like recess 14 that extends inwardly from aconcave surface 315 formed in one side of the electrode block.

A thin flexible metallic strip to has both of its ends anchored, such asby screws 17, to the side or block 3.3 in which surface i5 is formed.These screws are spaced closely enough so that the strip will normallybe bowed and assume either of the two stable positions indicated in PK}.1 (wherein the degree Oi catenary curvature is exaggerated for clarity).The spacing of screws 17 and the curvature of surface 15 are so selectedthat when the strip 16 is in one of its two stable positions, the stripwill contact surface 15' in such manner as to at least partially sealoil" the end of recess M.

The switching devices 19, it? are spaced with their respective recesseslid generally aligned and facing each other. A mechanical operatingconnection is provided between the spaced flexible strips in of therespective devices by a single intervening rod-like element 18. Thiselement makes end contact with each strip at the point wheredisplacement of each strip is greatest; namely, at a point midwaybetween the screws 17 and just opposite the corresponding recess.Element ll; is of such length that it will substantially contact eachstrip it? when one of the strips overlies its corresponding recess lidand the other strip is bowed the maximum degree away from its recess.Thus, motion will be transmitted from one strip through element l to theother strip; and hence, under stable conditions, both strips will beconcurrently disposed in their lettwardly flexed positions, as shown inFIG. 1, or in their rightwardly flexed positions. Thus, as the strips 16flex between these stable positions, element 38 will be displacedaxially a corresponding degree.

As illustrated, element if; has slidably guided contact with the wallsof aligned bores that extend through a container This container ispartitioned into three laterally spaced chambers 21, 22, 23, eachcontaining iercury or amalgam or some other electrically conducriveliquid. The element it; is formed of non-conductive material except fora sleeve 24 that is formed of electricaliy conductive material. Thissleeve is long enough to electrically interconnect the liquid in middlechamber with thatin either, but not both, of the end chambers 21, Thissleeve 2% encircles a reduced diameter portion of the rod-like clementlib so that the outer diameter of both that portion and remainingportion of the element are substantially equal. Hence, no conductiveliquid will flow between the chambers as the element 15 is moved axiallyin either direction relative to the container 20. In so moving, element18 will alternatively complete either of two circuits by selectivelyconnecting a wire 25 either to a wire 26 or to a wire 27.

Identical, but separate, control circuits are associated with eachswitching device ill, ll) to control their selective operation andconsequently control the displacement of element 13. Each controlcircuit comprises a high voltage power source 28 for charging an energycapacitor 29 when a switch Eli is closed. The source 28 and capacitor 29of each circuit are connected in parallel with the respective electrodes11, 12 through a switch 31.

In operation, assume initially that both switches 3t? are closed tocharge the corresponding capacitors that both switches 31 are open; andthat element 16 is positioned as shown in FIG. 1 to connect wire withwire 26. To connect wires 25 and 27 and disconnect wire 25 from wire 26,the switch 31 associated with device 119 is closed to apply a highpotential across the electrodes ll, 12 suflicient to break down the airgap therebetween. As the capacitor 2? associated with device 16discharges along the air gap, it will create an increase in air pressurewithin the corresponding recess 14. Because of its shape, that recess 14will act like a nozzle and focus the resultant shockwave against themidpoint of the flexible strip 16 of device lit. The shockwave energywill thus flex the strip inside out. In so doing, it will displaceelement 18 rightwardly for causing sleeve 24 to successively disconnectwire 25 from wire 26 and then connect wire 25 to wire 27. Also, aselement 18 moves rightwardly, it will transmit some of the shockwaveenergy from device Irtl to the flexible strip 16 of device Ill) forflexing the latter strip inside out to its other stable position inwhich it Will come to rest against concave surface 15 of thecorresponding electrode block 13. This will serve to define therightmost position of element 18, just as the leftmost position of saidelement is defined by contact of strip 16 with the electrode block ofdevice ltl.

Switch 31 of device lit) may now be opened. Upon subsequent closure ofswitch 31 of device ill, element 18 will be driven to its leftmostposition, in which it is shown, by a shockwave that is produced inrecess 14- of device Ill in the same manner as already described.

Thus, upon breakdown of the air gaps in first one and then the other ofthe devices ltl, iii, the contact element 18 will be displaced betweenits two stable positions; i.e., it will remain latched in each positionuntil positively actuated to the other position.

According to the variation of the invention illustrated in FIG. 2, thecontact element id is displaced to its leftmost position by shockwaveenergy upon breakdown of the gap in switching device lit, in the manneralready described. However, the element 18 is mechanically returnedautomatically to its rightmost position by a cam 32. The control ortriggering circuit for the electrodes ll, 12 of device it) contains thesame elements as in FIG. 1; but a circuit breaker cam CB has been placedin the triggering circuit to open said circuit while the high point ofthe cam 32 is in contact with element if. This cam CB is driven from thesame shaft as cam 32 and so disposed as to prevent damage to theapparatus which might otherwise occur if no cam CB were provided and theswitch 31. were closed while the cam 32 was positioned as shown in FIG.2.

It is to be understood that the switches 30, 31 shown in FlGS. 1 and 2are illustrated as being of the manually operable type for purposes ofsimplified illustration.

They may, of course, be replaced with other switches, operableelectrically, electro-magnetically or electronically. Also, the wettedcontact arrangement shown in FIGS. 1 and 2 and provided by containerfill may be replaced by other types of contact-making and breakingarrangements. Moreover, if preferred, the element 18 may be axiallydisplaced by shockwaveenergy in the manner herein disclosed forperforming some other type of useful work, not necessarily an electricalswitching function.

According to the embodiment shown in FIG. 3, a thin flexible strip 16ais cantilever-supported by being clamped at one end between an electrodeblock 13a. and a nonconductive (such as plastic) contact support 35.When in its free state, strip lea overlies a bore-like recess 14::extending inwardly from a flat surface 15a of the block 13a; and thefree end of the strip makes electrical connection with a normally closedcontact point 36 carried by block 136:.

When the gap between the tips of electrodes 11a, 12a is broken down,such as by circuitry described in FIG. 1, the resultant shockwavecreated in recess 14a will be focused against the flexible strip 16a anddrive it into electrical connection with a normally open contact point37 carried by the support 35. After the shockwave energy dissipates, theflexible strip 16a will be returned by its inherent resiliency to itsnormal position in which it is shown in FIG. 3. Hench, an electricalcircuit will normally be established between the flexible strip 16 andcontact point as except immediately following ionization of the air gapin recess Ma, thus providing what may be called a monostable switchingdevice.

In the modified arrangement shown in FIG. 4, a flexible strip 165 iscantilever-supported between electrode blocks 33b, 13c having respectivebore-like recesses 14b, that face each other and are substantiallycoaxially aligned at opposite sides of said strip. The tips ofelectrodes ill), 12b are separated by a gap within recess 14!); andelectrodes Me, 120 are separated by a similar gap in recess Me.

When unfiexed, the flexible strip 16b is spaced substantially equaldistances from the ends of the recesses 14b, 14c and also from contactpoints it) and 41. By associating permanent magnets 42, 43 with therespective contact points as, all, the relay will operate as a latchtype. In such case, the flexible strip lea will be held by the magnet 32or all in contact with the corresponding contact point 4% or 41 until itis actuated by shockwave energy into contact with the other of thecontact points. However, if this latch function is not desired, themagnets 42, 43 may be eliminated. In such case, the electrical circuitwill be completed through strip 16b and contact 40 only momentarilyafter the air gap is broken down in recess 14c; and, similarly, anelectrical circuit will be completed through said strip and contactpoint 41 only momentarily after the gap is broken down in recess 14b.

The following is a tabulation, given by way of example only, ofillustrative operate times that have actually been obtained withswitching devices of the type shown in H68. 1, 2 and 3, where:

E is elcctromotive force in volts;

C is capacitance in microfarads;

W is energy in joules;

S is the air gap in inches; and

0/1 is the operate time in microseconds.

(l) Latch Relay, as shown in FIGS. 1 and 2, using flexible strip (116)having an unclarnped length of 2 /2 inches, width of .150 inch, andthickness of .005 inch:

(2) Monostable Relay, as shown in FIG. 3, using flexible strip (16a)having an unclamped length of 1 inches,

width of .150 inch, and thickness of .005 inch:

(:2) To close Normally Open Point (37)- E o W s O/T (11) To openNormally Closed Point (36)- n 0 W s O/T 1, 000 .5 .25 12 1, 500 .5 .50 02,000 .5 1.00 7 2,500 .5 1. 50 0 1,000 .25 .13 15 1,500 .25 .2s 14 2,000.25 .50 1s 2, 500 .25 .78 12 1, 000 .1 .05 22 1,500 .1 .11 2,000 .1 .2018 2,500 .1 s1 17 While the invention has been particularly shown anddescribed with reference to preferred embodiments thereof, it will beunderstood by those skilled in the art that the foregoing and otherchanges in form and details may be made therein without departing fromthe spirit and scope of the invention.

What is claimed is:

1. Control apparatus comprising a movable member having two stablepositions in which it is selectively positionable to perform desiredcontrol operations,

a plurality of electrodes separated by a gap means disposed beside saidmember,

circuit means for applying an electrical potential to said electrodesfor producing a controlled electrical discharge across said gap means tocreate a shockwave, and

means for focusing said shockwave against said member to operativelyactuate it from one of its stable positions to another of its stablepositions.

2. Control apparatus comprising a flexible member anchored at at leastone end and selectively positionable in either of two stable positionsfor performing desired control operations,

a plurality of electrodes separated by a gap means disposed beside saidelement, and

means for applying an electrical potential across said electrodessuiiicient to ionize said gap means and pro duce a shockwave for flexingsaid member from one of its positions to another of its positions.

3. Control apparatus comprising a thin flexible strip,

means for anchoring the strip at both ends to provide a slight bowtherein,

a plurality of electrodes separated by a gap means disposed beside thestrip,

means for applying an electrical potential across said electrodes toionize said gap means and produce a shockwave, and

means for focusing the shockwave against substantially the point ofmaximum extension of the bowed portion of the strip thereby to flex thebowed portion inside out to an oppositely bowed position for performinga desired control operation.

4. A control apparatus comprising a flexible member anchored at at leastone end,

a plurality of electrodes separated by a gap means at one side of saidmember,

means for applying an electrical potential across said.

electrodes sufiicient to ionize said gap means and produce a shockwaveadequate to hex said member, and

an element disposed at the other side of said member and movabletranslationally by and upon flexing of said member thereby to perform adesired control operation.

5. Electrical switching apparatus comprising a movable member having twostable positions in which it is selectively positionable for controllingthe making and breaking of an electrical circuit,

a plurality of electrodes separated by an air gap means disposedadjacent said member, and

circuit means for applying an electrical potential to said electrodesfor effecting a controlled electrical discharge across said gap means toproduce a shockwave for operatively actuating said member from one ofits positions to another of its positions.

6. Electrical switching apparatus comprising a flexible switching memberanchored at at least one end,

a contact element operably connected to said member to make and break anelectrical circuit including such contact means,

means providing a recess which said member overlies when in one stableposition,

a pair of electrodes separated by an air gap provided within saidrecess, and

circuit means for applying an electrical potential across saidelectrodes for producing a controlled electrical discharge to break downsaid air gap and produce a shockwave that is focused toward said memberby said recess-providing means to actuate said member from said oneposition to another stable position.

7. A switch apparatus according to claim 6, wherein said flexible memberis anchored at both of its ends such as to have a preset bow overlyingsaid recess, said flexible member being of such configuration as tobuckle inside out as it moves from said one position to said otherposition, thereby to remain in said other position indefinitely untilpositively returned to said one position.

8. A switching apparatus according to claim 7, including cluding apermanent magnet associated with each contact point to maintain theflexible member engaged with such contact point until the flexiblemember is positively disengaged from said contact point by a subsequentforce.

l1. Electrical switching apparatus comprising a block of non-conductingmaterial having a nozzlelike recess in one side thereof,

a pair of electrodes supported by said block and having their tipsspaced by a gap existing within said recess,

a flexible switching control member anchored at both ends at pointsspaced closeenough together to how such member to one position in whichit substantially overlies and at least partially blocks said recess, and

circuit means for applying an electrical potential across saidelectrodes for producing across said gap 2. controlled electricaldischarge and consequent shockwave which is directed laterally by saidnozzle-like recess against said flexible member for buckling it insideout to another position in which it is oppositely bowed,

8 whereby said flexible member will remain in said 2,559,227 Rieber July3, 1951 other position until shifted therefrom by a subse- 2,824,928Hedlund Feb. 25, 1958 quent force. 2,901,580 Kelly Aug. 25, 1959References Cited in the file of this patent 5 2920250 Thomas et 1900UNITED STATES PATENTS OTHER REFERENCES 2,403,990 Mason July 16, 1946Parr, J. Frederick: Hydrospark Forming, The T001 2,552,389 Mason Sept.12, 1950 Engineer, vol. 44, N0. 3, March 1960, pp. 81-86.

2. CONTROL APPARATUS COMPRISING A FLEXIBLE MEMBER ANCHORED AT AT LEASTONE END AND SELECTIVELY POSITIONABLE IN EITHER OF TWO STABLE POSITIONSFOR PERFORMING DESIRED CONTROL OPERATIONS, A PLURALITY OF ELECTRODESSEPARATED BY A GAP MEANS DISPOSED BESIDE SAID ELEMENT, AND MEANS FORAPPLYING AN ELECTRICAL POTENTIAL ACROSS SAID ELECTRODES SUFFFICIENT TOIONIZE SAID GAP MEANS AND PRODUCE A SHOCKWAVE FOR FLEXING SAID MEMBERFROM ONE OF ITS POSITIONS TO ANOTHER OF ITS POSITIONS.